This invention relates generally to computer controlled systems and particularly to a system for providing a multi-bit input to the computer of such a system by depressing a single key on a keyboard.
Frequently with a computer controlled system, a keypad is used to provide input information to the computer. A single key is pressed to provide a multi-bit (typically 16 bit) input to the computer. An example of such a computer controlled system is a 3-in-1 lighthouse which is used to apply the black matrix to the inside surface of the faceplate panel of a color kinescope. In such a lighthouse, the panel and lensing/lighting system of the lighthouse are moved relative to one another to three different positions. At each position, a light is flashed to expose a photosensitive binder including the black matrix material through the apertures of a shadow mask which is mounted in the panel. Three positions are used because exposures are required at the three positions where the three colors of phosphors are subsequently applied to the panel. Accordingly, such a control system must be provided with an input that identifies the parameter and an additional input which establishes the value of the parameter. For example, the excursion distance the panel and lensing/lighting system move relative to one another requires that two inputs be supplied to the computer. The first input identifies the input as the excursion distance and requires pressing a particular key on the keypad. The second input sets the actual distance traveled and requires pressing a different key. Accordingly, every parameter supplied to the system requires a first multi-bit input to identify the parameter and a second multi-bit input to establish the value of the parameter.
The instant invention fulfills these requirements by the provision of a system for inputting multi-bit inputs to a computer by the depression of a single key on a keyboard pad.